Tourists play at a beach covered by a thick layer of green algae in Qingdao, China, on July 3, 2013. A large quantity of non-poisonous green seaweed, enteromorpha prolifera, hit China's Qingdao coast last month. More than 20,000 tons of such seaweed has been removed from the city's beaches. This has now become an annual summer event. (Photo by Whitehotpix/ZumaPress.com)

Toure, a Gambian salt harvester, holds a basket filled with the salt collected from the crust of the bottom of the Lake Retba (Pink Lake) in Senegal on March 16, 2021. Lake Retba, divided from the Atlantic Ocean by a narrow corridor of dunes, owes its name to the pink waters caused by the Dunaliella salina algae and is known for its high salt content, up to 40% in some areas. (Photo by Marco Longari/AFP Photo)

Eghy (L) uses his makeshift snorkel as his colleague lifts up green mussels to their boat in Jakarta Bay, Indonesia, April 20, 2016. (Photo by Reuters/Beawiharta)

Workers tend green onion plants among nearly 1,000 acres of terracing in fields in the Majalengka Regency of West Java in Indonesia in July 2021. (Photo by Andika Oky Arisandi/Solent News)

A swimmer disguised as Superman dives into the lake during the 78th “Coupe de Noel” (Christmas cup) swimming race in the Lake Geneva, on December 18, 2016 in Geneva. More than 1800 participants took part in the event, a 12-meter-long swimming off the Geneva's bank in the 7 degrees Celsius cold water. (Photo by Fabrice Coffrini/AFP Photo)

Czech fishermen sort fish during the traditional Carp haul at Lake of Dvoriste near Smrzov village, Czech Republic, 02 November 2015. Carp, the traditional Czech Christmas Eve dinner, is harvested primarly from the region of southern Bohemian lakes. (Photo by Filip Singer/EPA)

A worker lays rails across the bed of a drained area of a lake used for the production of salt at the Sasyk-Sivash lake near the city of Yevpatoria in Crimea, October 5, 2014. The area has a long tradition of salt production, prepared from salt flats flooded with water from the Black Sea. (Photo by Pavel Rebrov/Reuters)

In this aerial view fishing boats are seen on the shore of the Lake Malawi at the Senga village on May 20, 2019 in Senga, Malawi. Hundreds of local traders gather each morning and afternoon at Senga, but fish populations are falling in Lake Malawi, Africa's third largest body of freshwater. (Photo by Gianluigi Guercia/AFP Photo)